Ghoul Grabber




Introduction: Ghoul Grabber

In this instructable I will be teaching you how to build:

A step sensor for less than a dollar (or even free!) (I was the first to post this!)

A delayer(to power your items for a given amount of time (the most simpe way possible)

And a ghoul grabber

That's right, you get 3 for the all low price a couple of dollars!

The step sensor is steps : 1-10

The delayer are steps: 10-15

The ghoul grabber is steps: 15-27


Step 1: The Step Sensor

You can make a good, reliable sensor for less than a dollar! All you need is some aluminum foil and paper! This type of sensor is really just a giant momentary, normally on, switch.

Step 2: Materials

Roll of heavy duty aluminum foil

A roll of paper (used in stuff like type writers and god knows what, you can buy them new or at garage sales/thrift stores)

That's it!

Step 3: Measure You Walkway

measure the walkway in front of your house that leads to your door. Mine was 42 inches wide

Step 4: Cut the Paper

cut 6 strips of paper so that the length of each paper is 2 inches longer than the width of your walkway, so I cut each piece of paper 44 inches long.

Step 5: Cut the Aluminum Foil

Cut the aluminum foil the same length as the paper, but this time you only need two sheets.

Step 6: Tape the Paper

tape two sheets back together so that it's now almost 2x as wide as before. Do this 3 times so you have 3 sheets of paper. This step is necessary because the width of the aluminum foil is wider than the paper.

Step 7: Turn Paper Into Fish Gills

using your hobby knife, cut strips out of one of the sheets of paper. Make sure that each strip is less than 1 cm wide or you'll run into problems later. The design of your cuts do not matter.

Step 8: Glue Foil to Paper

glue one strip of aluminum foil to one of the sheets (one of the non cut-up ones) in the center. Do the same for the other one. Now you have a sheet of paper with aluminum foil stuck to it, a paper that looks like gills, and another sheet that has aluminum foil glued to it.

Step 9: Put It All Together

sandwich the layers of material like this:

gill paper

Step 10: Tape It and Your Done

tape the edges together (not too tightly) and you're done! Whenever you step on it the 2 pieces of aluminum foil touch, acting like a momentary switch.

Step 11: Delayer/timer

now you have your sensor you need a delayer. What this does it keep your motor (or whatever) on even after you step off of the sensor for a predetermined time.

Step 12: Materials


electrolytic capacitor(s)

12volt spdt relay (from radioshack, I used this one )

jumper wires and alligator clips

Step 13: Choosing a Capacitor

I used 3 capacitors (I couldn't find one big one) in parallel to get my timing device. When choosing your capacitor about 1100 uF equals 1 second. so to get 5 seconds (I think it's a good time) then use 5500 uF.

Step 14: Schematic

can't really help you hook everything up, but here's the schematic I came up with.

Step 15: Hook It Up

hook all of the connections up and your done! I used a breadboard because halloween is one day a year, and I want to keep my parts, such as the relay.

Step 16: The Ghoul

the ghoul is the main part of this instructable, yet can be made within an hour for mere dollars.

Step 17: Materials

motor (make sure it's strong, mine wasn't strong enough so I couldn't add to many decorations)

a skull (picked up at Michaels for 5 dollars)

2x 24 inch piece of wood

2x 20 inch piece of wood

1x 12 inch piece of wood

1x 6 inch piece of wood

1x 4 inch piece of wood

NOTE: the kind of the of the wood doesn't really matter, between 1 and 2 inches wide are good, the thickness of the wood should be kept to a minimum, like around 1/8 to 1/4 of an inch.

5 inch long dowel

some scrap wood

some big piece of wood for a base

old white dress shirt

8x nuts and bolts

a bunch of washers

Step 18: Drill the Wood

note that all holes are to be centered, but it doesn't matter a whole lot
note that all holes should be wide enough so that the bolt slips through easily (but not the head)

on both 2 foot pieces of wood drill a hole on each ends (about 1 inch from the end). Next drill a hole in the center of both pieces of wood. You should have drilled a total of 6 holes.

on both ends of the 1 foot piece of wood drill a hole 1 inch from the end.

for the 20 inch piece of wood line up the bottoms with the 1 foot piece of wood and drille holes so that it's like the 1 foot piece of wood, with more wood sticking out. the holes should be around 1 end, and the center.

for the 6 inch drill on both sides about 1/2 to 3/4 of an inch from the edge.

on the 4 inch piece of wood do the same as the 6 inch piece of wood

Step 19: Connect Everything

connect everything as you might expect with nuts, bolts and washers. the 2x 2 foot woods are parallel, the 12 inch wood bisects it, and the 2 20 inch woods extend from the ends of the 2 footers. Glue on the dowel a bit off center as shown in the picture. Don't worry about the 4 and 6 inch wood yet

Step 20: Make the Base

elevate a little island on your big board so that you can rest your structure on it. glue the board to the 12 inch wood like in the picture.

Step 21: Make a Crank

attach the 2 short pieces of wood as shown.

Step 22: Drill a Hole in the Structure

depending on how strong your 12 volt motor is you drill a hole in certain places. the stronger your motor the closer to the center you get, the weaker the motor the closer to the "arms" you get. Don't mind the motor in this picture.

Step 23: Attach the Motor

attach the motor to the crank you made.

Step 24: Attach to the Structure

attach the crank to the hole you drilled in step 22. You can then use a clamp to hold the motor down.

Your ghoul is now ready, you now just need to make it look scary!

Step 25: Clothe It

put a dirty shirt on the structure. if you want to you could even drop some red food dye for blood. I had to cut my shirt because my motor was too weak because the shirt was dragging on the floor.

Step 26: Glue the Skull

glue the skull onto the dowel and your done!

Step 27: Taking It Further

if you want to you could add on another relay and have that control power going to speakers that are playing ghoul like sounds. Alas I don't have an MP3 player or speakers.

YOU'RE DONE!!! WOOHOOOO!!!!!11 (<-see the one there?)!!! You should be proud!

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    13 Discussions


    2 years ago

    Great idea. I love Halloween gags, it's a time of year that we can let our imaginations run wild.


    6 years ago on Step 27

    I would imagine a windshield wiper motor with a crank already attached would work well for this rig. Nice work for cheap.


    12 years ago on Introduction

    Thanks for posting your gag. I'm not very experienced in reading schematics, but your pictures are helpful. I'm guessing the jumpers and alligator clips are going to the switch (paper and foil). Also Where would one get a motor at short notice. I'd like to build one this weekend for Halloween. In answer to your video question, The video is there, I can play the video, but it is so dark I can't make anything out. p.s. I'll take your schematic into radio shack and see if they can help me understand how to put the electronic part together. :)


    Reply 12 years ago on Introduction

    thanx! I got my motor out of an old printer, anything that's somewhat big and moves usually has a good motor. If you're having trouble reading the schematic I'll try and word it out to you. You have a 12volt power supply. The sensor acts as a momentary switch. When the switch is connected it charges the capacitors and turns on the relay. When you step off the switch the capacitors discharge into the coil of the relay for a predetermined time. You connect the motor to the common contact and the normally open contact on the relay. So now the motor turns on when the relay is on. Step on switch charges capacitors and turns on relay relay connects contacts and allows current to flow so that the motor turns. the capacitors charge the capacitor discharges into the relay the relay stays on for a couple of seconds the capacitors are totally discharged and the relay turns off.


    Reply 12 years ago on Introduction

    Thanks for your additional help. Also I did increase my screen brightness and was able to make out the video. Happy Halloween :)


    Reply 12 years ago on Introduction

    oh and if you turn up the screen brightness to about 70 the video shows up fine.


    12 years ago on Introduction

    Can everyone see the video? I can only see it when I log in


    12 years ago on Introduction

    Great project - instead of just a plain motor, using one with a gear-reduction on it would be a really good idea so that it has some oomph when it comes to moving the arms. I'm in the process of building a pneumatic zombie right now. Will post later. I like the step switch, and the capacitor relay trick is quite sneaky.


    Reply 12 years ago on Introduction

    thankyou! I was orginally going to try a gear reduction system but I always ran into problems, but it's a good idea if you can accomplish it


    Reply 12 years ago on Introduction

    sure, but I must warn you that you can make one soooo much better than mine. I only had a weak motor. If you had a motor stronger than mine it would be like 10x better. I'll post a video later today


    Reply 12 years ago on Introduction

    i've got lots of motors, i'm sure i can find one that'll work


    Reply 12 years ago on Introduction

    I'll post that video tonight, have to wait for it to get dark outside